PROJECT ABSTRACT Every year, more than two million older Americans (aged 65 and older) suffer from an episode of delirium during their intensive care unit (ICU) stay. Advances in the management of critical illness have improved critical illness survival rates especially among older adults. However, as many as 70% of ICU older survivors who had an episode of delirium are left with newly acquired cognitive impairment that can have disabling long- term consequences for both patients and their informal caregivers. Currently, there are no effective and scalable recovery models to remediate or treat ICU acquired cognitive impairment and its deleterious effects on quality of life and independence of this growing segment of older ICU survivors. Over the past five years, interdisciplinary team of scientists at Indiana University Center for Aging Research developed a novel, home-based cognitive and physical exercise program to reduce the societal impact of cognitive impairment. The team is proposing to conduct a randomized controlled trial (RCT) called ?Decreasing Alzheimer's Disease and Related Dementias after Delirium-Exercise and Cognitive Training (DDD-ECT)? to evaluate the efficacy of 12 weeks of combined physical exercise and cognitive training intervention on the primary outcome of cognitive function among older ICU survivors in central Indiana who had an episode of delirium during their ICU stay. Importantly, we propose to deliver these interventions via a facilitator-led, small group format using internet-enabled, multiparty-videoconference delivered directly into the participants' homes. The trial has the following aims: 1. Determine the effect of the combined physical exercise and cognitive training on the cognitive function of older ICU survivors at 3 and 6-months follow-up. 2. Determine the effect of the combined physical exercise and cognitive training on physical performance, anxiety and depressive symptoms, and quality of life of older ICU survivors at 3 and 6-months follow-up. 3. To examine the mechanisms of action of combined training. Achievement of the aforementioned aims will provide an efficacious therapy to improve cognitive outcomes among ICU survivors along with highlighting the involved neurobiological pathways. The findings will aid in moving the field forward towards reducing the burden of Alzheimer's disease and related dementias.